ImportError: cannot import name 'PretrainedBertIndexer'

[Mayar2009]

when trying to understand bert_text_classification.ipynb

this part of notebook

from allennlp.data.token_indexers import PretrainedBertIndexer

token_indexer = PretrainedBertIndexer( pretrained_model="bert-base-uncased", max_pieces=config.max_seq_len, do_lowercase=True, )

apparently we need to truncate the sequence here, which is a stupid design decision

def tokenizer(s: str): return token_indexer.wordpiece_tokenizer(s)[:config.max_seq_len - 2]

gives this error

ImportError Traceback (most recent call last) in () ----> 1 from allennlp.data.token_indexers import PretrainedBertIndexer 2 3 token_indexer = PretrainedBertIndexer( 4 pretrained_model="bert-base-uncased", 5 max_pieces=config.max_seq_len,

ImportError: cannot import name 'PretrainedBertIndexer'

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allennlp version used is 1.0.0

seems version differ , I could not find the solution what should I do?